In general, wet tissues are sealed and housed in a container or package so as to keep their wet state before use or when unused. These wet tissues are stacked, such that they have overlapping portions between the upper and lower wet tissues, so that they are consecutively and sequentially pulled out of an outlet provided in the container or package. When the wet tissue at the uppermost position is pulled out, a portion of the succeeding wet tissue is protruded from the outlet of the container. This is generally called the "pop-up type". The conventional wet tissue stacked body of this "pop-up type" will be described with is reference to the drawings.
One example of the conventional wet tissue stacked body, as shown in FIG. 14, is formed in the following manner. First, a wet tissue 61A is folded in two along its center line 64 as a folding line, as shown in FIG. 12(A), such that a wet tissue 61B having such a shape as shown in FIG. 12(B) is produced. In FIG. 14, the wet tissues 61B are stacked such that a lower half 63 of the upper wet tissue 61B is sandwiched between an upper half 62 and a lower half 63 of the lower wet tissue 61B.
When the upper wet tissue 61B is pulled out, the upper half 62 of the lower wet tissue 61B, which is put on the lower half 63 of the upper wet tissue 61B, is pulled up together toward the outlet (not shown) to be pulled out from the outlet. Thus, the upper half 62 of the lower wet tissue 61B comes out of the outlet so that the wet tissues can be pulled out consecutively one by one.
However, in the wet tissue stacked body shown in FIG. 14, the overlapping area between the lower half 63 of the upper wet tissue 61B and the upper half 62 of the lower wet tissue 61B is as large as about one half of the area of the wet tissue 61A before being folded. Therefore, when the upper wet tissue 61B is pulled out, the length of the protrusion of the succeeding lower wet tissue 61B becomes as large as about one half of the length of the wet tissue 61A before being folded.
If the protrusion of the wet tissue is too large, it can not be confined within the area of a cover which is usually provided with the container or package to cover the outlet. As a result, the protrusion partially extends out of the cover. Then, the wet tissue dries up at this portion extending out of the cover. Moreover, when the protrusion partially extends out of the cover, it is difficult to close the cover reliably. This lowers the sealability of the container or package, so that the overall wet tissue stacked body is liable to dry up.
FIG. 15 shows another example of the conventional wet tissue stacked body. The wet tissue stacked body shown in FIG. 15 is formed in the following manner. A wet tissue 71A, as shown in FIG. 13(A), is folded back at its end portions toward the opposite faces along the folding lines 75 and 76 which divide the wet tissue 71A substantially in three such that a wet tissue 71B having such a shape as shown in FIG. 13(B) is formed. As shown in FIG. 15, the wet tissues 71B are stacked such that a lower portion 72 of the upper wet tissue 71B is sandwiched between an upper portion 74 and an intermediate portion 73 of the succeeding lower wet tissue 71B.
In this construction, the overlapping area between the lower portion 72 of the upper wet tissue 71B and the upper portion 74 of the lower wet tissue 71B is as large as about one third of the area of the wet tissue 71A before folded. Therefore, the length of the protrusion of the succeeding lower wet tissue 71B becomes shorter than that of the example shown in FIG. 14. However, since the wet tissue 71B is folded in three, the stacked body composed of a plurality of wet tissues 71B becomes too thick.
Disclosed in Japanese Patent Laid-Open No. 213453/1995 (which corresponding U.S. Pat. No. 5,497,903) is a wet tissue folding structure which allows the wet tissues to be consecutively pulled out. This wet tissue folding structure is shown in FIG. 16. In this folding structure, the lower half 63 of the wet tissue 61B shown in FIG. 12(B) is further folded in two along a folding line 65 to form a wet tissue 61C shown in FIG. 12(C). As shown in FIG. 16, the wet tissues 61C are then stacked such that the upper half 62 of the lower wet tissue 61C is sandwiched between the upper half 62 and an intermediate portion 66 of the upper wet tissue 61C.
Here, as shown in FIG. 16, the wet tissue 61C is further indicated by 61C1, 61C2 and 61C3, in order from the top. When the wet tissue 61C1 is pulled out, the righthand half of the upper half 62 of the wet tissue 61C2 is pulled up together with the intermediate portion 66 of the wet tissue 61C1 and protruded from the outlet. In this folding structure, therefore, the length of the protrusion of the succeeding lower wet tissue 61C is optimized to about one quarter of the length of the wet tissue 61A before being folded. Moreover, the stacked body does not become too thick.
However, the folded wet tissue 61C composing the wet tissue stacked body shown in FIG. 16 is formed by folding the wet tissue 61A along the widthwise center line 64 and then by folding only the lower half 63 along the folding line 65. As a result, the widthwise center line of the folded wet tissue 61C is not identical to that of the unfolded wet tissue 61A. Therefore, the wet tissue has to be supplied to the folding step while being guided such that its center is widthwise shifted. This makes it difficult and seriously troublesome to adjust and stabilize the folding line at a correct position on the supply line.
At the folding step, moreover, because the center of wet tissue is liable to be offset, the center line 64 or the folding line 65 is liable to move out of position. With this discrepancy in the folding size, the overlapping area between the upper half 62 of the lower wet tissue 61C and the intermediate portion 66 of the upper wet tissues 61C fails to take one quarter of that of the unfolded wet tissue 61A accurately, so that the length of the protrusion of the wet tissue cannot be fixed. In addition, there may be such a case that the folding line 65 of the upper wet tissue and the folding line 65 of the lower wet tissue overlap each other. As a result, the central portion of the stacked body may become thick.